In the fall of 1863, the 1st Kentucky Brigade formed a part of General Braxton Bragg's attempt to counter UnionMajor GeneralWilliam Rosecrans' offensive against Chattanooga, Tennessee.[18] At 9:30 am on September 20, 1863, the divisions of Generals Breckinridge and Patrick Cleburne were ordered to move forward.[17] Helm's brigade and the others in Breckinridge's division drove into the Federals' left.[17] General Cleburne's division, which was intended to strike near the center of the line, was delayed by heavy fire from Union soldiers, leaving the left flank unguarded.[17] Repeated attempts to overwhelm the Federals were in vain, though some of Helm's Kentuckians and Alabamans managed to reach within 39 yards (36 m) of the Federal line.[17] In less than an hour of the order given to advance, fully one third of the Orphan Brigade had been lost.[19] While the remainder of Helm's men clashed with the Union line, a sharpshooter from the 15th Kentucky Union Infantry shot Helm in the chest.[17] Bleeding profusely, he remained in the saddle a few moments before toppling to the ground.[20] After being carried off the battlefield, Helm's surgeons concluded that his wounds would be fatal.[17] Helm clung to life for several hours. Knowing that his health was deteriorating, he asked who had won the battle. When assured that the Confederates had carried the day, he muttered: "Victory!, Victory!, Victory!".[21] On September 21, 1863, Gen. Helm succumbed to his wounds.[17]

Following his death, Abraham Lincoln and his wife went into private mourning at the White House.[22] Mary Lincoln's niece recalled: "She knew that a single tear shed for a dead enemy would bring torrents of scorn and bitter abuse on both her husband and herself."[23] However, the widowed Emilie Todd Helm was granted safe passage to the White House in December 1863.[24]

In an official report of the Battle of Chickamauga, General Daniel Harvey Hill stated that Benjamin Helm's "gallantry and loveliness of character endeared him to everyone."[22] In a letter to Emilie Todd Helm, General Breckinridge said, "Your husband commanded them [the men of the Orphan brigade] like a thorough soldier. He loved them, they loved him, and he died at their head, a patriot and a hero."[22]

McMurtry, Robert (1943). Ben Hardin Helm: "rebel" brother in law of Abraham Lincoln, with a biographical sketch of his wife and an account of the Todd family of Kentucky. Chicago: Civil War Round Table.